1. Field of the Invention
This invention relates to radar technology, and more particularly, to a method and system for radar tracking of a moving target (such as an air-to-air missile) from a moving station (such as a jetfighter) with improved accuracy and performance.
2. Description of Related Art
A radar system is a radio-based surveillance system that uses electromagnetic waves to identify the range, altitude, direction, or speed of moving or fixed objects such as aircraft, ships, and motor vehicles. In operation, a radar system is capable of emitting a beam of radio wave toward the area under surveillance, and if a target exists in that area, the emitted radio wave will be reflected back. The reflected radio wave is then received by the radar system and analyzed to determine the position, speed, and acceleration of the target.
Radar systems are categorized into ground-based type and airborne type. The airborne-type radar systems are installed on airplanes such as jetfighters for detecting air-to-air missiles or nearby airplanes. In this type of application, since the radar system and the target are both moving, the detected radar data represents the relative position, relative speed, and relative acceleration of the target.
Many research efforts have been conducted on airborne radar systems intended for air-to-air missile detections. For example, the technical paper “WAVEFORM DESIGN PRINCIPLES FOR AUTOMOTIVE RADAR SYSTEMS” authored by H. Rohling and M. M. Meinecke, IEEE Radar, pp. 1-4. October 2001, proposes a radar system that utilizes a hybrid FSK/LFM (Frequency Shift Keying & Linear Frequency Modulation) technique for detection of relative distance and relative speed between the radar system and the target.
One drawback to the aforementioned radar system, however, is that the hybrid FSK/LFM sensor is only capable of detecting the range and speed of the target, and incapable of detecting the acceleration.
Moreover, many conventional radar systems utilize trilateration to obtain the range, velocity, and acceleration of the target from a collection of raw radar data. One drawback to the trilateration process, however, is that it would undesirably degrade the S/N (signal-to-nose ratio) of the original radar data.